Thanks for the speedy update. I actually retired from lecturing in a UK University last week and the impact of online learning is going to be massive in Higher Education in the very near future. Increasingly students are going to want to learn from online resources (even those student who are studying onsite as well as via distance learning). eBooks and web books are likely to be important element in providing students with the opportunity of studying at times and places that suit them but the 'book' resources need to be interactive and media rich. iBook Author on Mac OS can certainly do this and apps such as Book Creator on the iPad can as well ...may be Calibre on the PC platform can too (not tried this) but the workflows offered by Xara when placeholders are used to link into Web2.0 services allow this kind of interactivity to be built in. Of course this approach does usually need an internet connection to deliver the interactive services but for most students this is increasingly available. The appeal of the web doc format is ironically the linear format which can be scrolled (would be nice if it could be flipped) on mobile devices.....another major change in Higher Ed!

I'd be interested in any further musings on the possibility of place holder issue in the web document format.
Thanks again,
Pwalder